1. Qian Zou:
Department of Information, Chengdu University of Technology, Chengdu 68, Shichuan, China
2. Huajun Wang:
Department of Information, Chengdu University of Technology, Chengdu 68, Shichuan, China
3. Wei Huang:
Department of Information, Chengdu University of Technology, Chengdu 68, Shichuan, China
4. Jin Pan:
Department of Computer, Guiyang University, Guiyang 550005, Guizhou, China